Leishmania sp. detection and blood-feeding behaviour of Sergentomyia minuta collected in the human leishmaniasis focus of southwestern Madrid, Spain (2012-2017)

Abstract

Phlebotomine sand flies are the only known vectors of Leishmania spp. protozoan which causes leishmaniasis in 98 countries. In Spain, 11 sand fly species are described, but only Phlebotomus perniciosus and Phlebotomus ariasi are proven vectors of the disease. On the other hand, Sergentomyia minuta is one of the most abundant and ubiquitous sand flies in this territory, although scarce information is available about this species. Sand flies from this genus are known for their preference to feed on cold-blooded animals and are traditionally involved in the transmission of reptile Leishmania. However, studies have suggested that Sergentomyia spp. could be implicated in the transmission of human pathogenic Leishmania. This study analyses blood meal preferences and Leishmania sp. infection of S. minuta sand flies from the largest human leishmaniasis outbreak in Europe. Sand flies were collected during entomological surveillance carries out from 2012 to 2017 in the active season of these dipterans, from May to October. Molecular detection of Leishmania spp. showed 68 positive specimens of S. minuta out of 377 (18%). The analysis of blood meal preferences by amplification of 359 bp fragment of cytochrome b gene revealed that blood preference of S. minuta is not only limited to reptiles, but they also feed on mammals, including humans. Results suggest the presence of a Leishmania sp., related to Leishmania tarentolae, cycle in S. minuta from the studied area. Although there is no evidence about its incrimination in the L. infantum transmission more investigation is needed to elucidate the intravectorial cycle of Leishmania spp. in S. minuta sand flies, their feeding behaviour and their potential contribution in Leishmania spp. epidemiology in the country.